Paper product



atented Dec. 17, 1929 CARLETUN ELLIS, 01E MOIN'ICLAIR, NEW JERSEY, ASSIGNOR TO ELLIS-FOSTER- CU'MPANY, A CORPORATION OF NEW JERSEY rarnn rnonuc'r Ito Drawing.

This invention relates to a paper product containing oxidized parafin wax, and the like, and to containers and container closures made from such paper material.

a This application is derived in large measure from my copending application Serial No. 107,461, filed November 15, 1928.

Oxidized parafin may be prepared by blowing a current of air or oxygen, or other oxy- 101 gen-containing gas through the molten material for a period of several hours, the temperature usually ranging from 160200 C. Oxygen goes into combination and to a certain extent fatty acids are formed together with various other oxygenated products. For the purposes of the present invention I prefer to carry the treatment only to a stage of incipient oxidation, the blown material containing a minimum of fatty acids, and the 2 like. Preferably in the case of wax the oxidation is merely suficient to somewhat reduce the greasiness of the wax and permit it to disperse more readily in an aqueous medium. By blowin wax for several hours at a temperature o160 C. but stopping the operation before deep-seated changes take place, a product which has been thus subjected to incipient oxidation results which is desirably employed in carrying out the purposes of the present invention.

The blown wax in a stage of inci ient oxidation is mixed with pulp, preferab y in the beater en no, or any other suitable stage in advance 0 actual formation into a sheet.

Two or three per cent by weight of the blown n wax, based on the paper material, may be introduced advantageously in this manner. Wax in this proportion, or even in lesser rela tive amount creates a desirable waterproofing efiect. a

The paper stock may be ordinary sulphite pulp, or it may be derivedfrom pulp produced by other processes of treating wood, or mixtures of pulps obtained from difi'erent t5 processes, In some cases gro wood, or

1928. Serial No. 286,485.

mixtures of ground wood with sulphite pulp or other pulp may be employed. The invention is not restricted to paper made from various forms of wood pulp, but may include stock made, for example, from jute and analogous fibres.

Dificulty has arisen in the past in the endeavor to use parafin wax in paper pulp due to clogging of the felts and screens with wax. In the present invention it is proposed to oxidize the wax to a stage sufficient to render its dispersion in water to be very thorough and permit of more effective occlusion of the dispersed blown wax by the wet paper pulp.

The exact degree of waterproofing or water resistance created depends, however, on the requirements of service conditions, and in some cases a waterproofing efiect of comparatively slight degree may be all that is required, while in other cases, a much more substantial degree of water resistance is needed. The blown wax therefore, should be used in such proportion as meets the specific requirements inhand.

The blown wax may be used in conjunction with rosin size, or other paper sizing agent. Alum, aluminum hydrate and various other coagulating agents for size may be used as required.

Instead of using the harder and more expensive grades of parafin wax, it is possible to use in the present invention various cheaper grades of wax including scale wax or waxwhich has been softened with various oils. Thus in some instances I prefer to employ the emulsion or dispersion of a mixture of wax and a good grade of petroleum oil, such mixture having been air-blown to at least a state of incipient oxidation. For a very high grade paper I may employ a blown mixture of wax and one of the so-called medicinal petroleum oils, of which products oil such as Nujol or Markol are typical. For lower grades of paper, especially when color is not important, various petroleum oils admixed which advantageously ma with wax may be blown to yield an oxidized product which when dispersed in an aqueous medium may be readily incorporated in the wet paper pulp.

While I have specified wax in particular, I may include mixtures of paralfin wax in the oxidized form with other waxes such as carnauba, candelilla, Montan, ceresin, and the like. Tt is also possible to make a mixture of waxes and blow these to oxidize them simultaneously and prepare the dispersion from this composite oxidized waxy material. Thus paraffin wax with 5 to 10 er cent of montan wax may be blown with air at a temperature of say, 170 C. for five hours. In like manner blown mixtures of paraflin wax, petroleum oil and montan wax or other wax of a character different from parafin wax may be blown and thus oxidized.

The dispersion ofthe oxidized material may be madein various ways, preferably with the aid of one or more emulsifying agents such as soap, alkali, starch, bentonite, silicate of soda, and the like. Thus a few per cent of stearic or oleic acid may be melted with the oxidized paraflin and this composition emulsified with a hot, dilute, aqueous solution of caustic soda or ammonia. The ammonia composition is preferable in some cases because any free ammonia may be removed Very readily. Or, silicate of soda may be incorporated with the oxidized material and suffieient water to produce a creamy dispersion, and the mixture passed through an emulsitying apparatus such as a colloid mill. Using a colloid mill, the amount of dispersing agent may be quite small. This is advantageous when ordinary soaps are employedbecause these tend to produce foaming in the beater and therefore the proportion of these should be kept at a minimum. Less than 1 per cent of potassium or sodium oleate may be employed to make a satisfactory dispersion of oxidized parfiin wax in water. *The dispersion may contain about 50 per cent of wax and yet be readily handled.

As indicated above, the oxidized paraifin emulsion may be added to the beater engine be done at the time the paper stock is c arged thereinto. After thorough mixing in the usual manner in the beater a quantity of rosin size or any other desired sizing agent may be added and such size set in the usual manner with alum or with any other setting agent. The addition of rosin size or similar sizing agent is, however, not necessary in making various forms of paper, it being proposed to produce paper without a sizing agent of a resinous character, if so desired, employing solely the oxidized material aforesaid to create adequate water resistance for the purpose in hand.

A paper pulp which contains a substantial proportion of hydrocellulose is advantageous in assisting in the fixation of the oxidized wax. The hydrocellulose may be added to the pulp or formed in it in any suitable manner.

The invention may be illustrated by the following: 7

A mixture of equal parts by weight of sulphite pulp and ground wood is agitated in Water in the beater with a dispersion of oxidized parflin wax suflicient to introduce about 4 per cent ofwax into the finished paper. The dispersion of the blown wax is made by Violent agitation of equal volumes of the wax and a l per cent solution of sodium or potassium oleate. Agitation in the beater is continued until hydrocellulose is formed to a considerable extent. After thorough admixture in this manner rosin size is added suificient to introduce 1 or 2 per cent of rosin or resinate and this rosin size is set by alum, either already present in the beater,

or added after the rosin size has been incorform, or built up in a plurality of layers, T

include under the designation paper these and other varied forms ofsheeted paper pulp.

The sheet is then calendered, preferably hot, and the particles of oxidized wax, 0x1- dized oil, and so forth, are thus further disseminated through the fibrous mass (and into the fibres thereof) composing the sheet. In this way an enhanced degree of water resistance is obtained.

The procedure of the foregoing illustration may be varied in different ways, as for example, a cheaper paper stock may be made by utilizing 3 parts by weight of ground Wood to 1 part of sulphite or sulphate pulp. The oxidized waterproofing material may be" a blown mixture of paraflin wax containing 10 to 20 per cent of hydrocarbon oil. The em ployment of the blown hydrocarbon oil may be desirable in operations where the paper is to be printed. In other words, the illustration set forth depicts merely one procedure and since numerous variations are possible, it is to be understood that the invention is not restricted in any manner by the specific character of the illustration.

Paper of suitable thickness produced in this manner, for example, of a thickness between 30 and 40 points, may be employed to make paper discs employed as closures for containers, especially milk bottles, by punching into disc form. These discs, containing a diameter such that they will seat tightly on the mouth on the bottle. There is thus obtained a closure for containers, said closure being made from paper carrying oxidized paraffin. Stated in another form, a container closure is produced comprising paper carrying oxidized paraflin wax introduced into the paper from an emulsified condition. As a product there is obtained the paper disc Waterproofed with oxidized paraflin, with or without other oxidized hydrocarbons. The features of this disc have been set forth rather fully in the aforesaid patent" application Serial No. 107,461, and for further details reference is made to said application.

Larger discs may be punched which can be drawn into the form of a hood cap to be placed about the mouth of the bottle to serve as a cover therefor.

In addition to these specific parts of containers, it should be understood that the entire container may be made from paper or pulp containing blown hydrocarbons. Thus, the walls and bottom of a container for milk may be made of board carrying suflicient oxidized wax to render such container tight and water resistant. Boxes for various foods, oyster pails, ice cream containers, and the like, may be produced from paper stock containing the blown wax or such Wax with blown petroleum oils.

0 As pointed out in Serial No. 107,461 it is important in making paper for food products to avoid the introduction of any substances which will possess strong odors and have a contaminating influence on food products such as milk, butter, and the like. Therefore, in preparing paper for such food product containers, I prefer to avoid substances such as blown tars, blown asphalts, and the like, which would be of a contaminating character and which further being dark in color would discolor the paper. Preferably, there- 'fore, I employ oxidized hydrocarbons which are light in color, free or substantially free from odor and which do not impart any objectionable taste to-the food material in contact therewith. If oxidation of the parafiin wax is carried to a stage where dark colored resinous substances or strongly odoriferous aldehydes, and the like, result, these when present in paper used in packing foodstufi's may exert a contaminating influence. For such purp0ses, therefore, I prefer to keep the oxidation within that range where resinous substances substantially are not formed and the physical appearance of the wax which has been subjected to incipient oxidation is only very slightly altered.

In the illustration set forth above 4 per cent of the oxidized waxy material is recompaper and using blown wax, I may increase the proportion to produce the desired waxed efiect.

Paper which has been made with the aid of the blown wax may, if desired, be superficially waxed, either with the ordinary paraiiin wax or with the blown wax, or with any other waxy material or mixture. Hence if the paper disc milk bottle closures formed with the aid of the blown wax require a waxy surfacing for any reason such treatment is not precluded.

It should be understood that I 'am not precluded from adding unoxidized oils and waxes to the blown wax or blown mixtures of hydrocarbons, when for any reason such admixture is desired, as for example, to cheapen the product.

In Patent No. 1,607,519 to Carleton Ellis, granted November 16, 1926, there is a disclosure of the use of oxy-paraffin in dispersions employed for waterproofing paper. But that companion patent is directed to rosin sized papers containing wax, and more particularly fibrous material produced from pulps containing hydrocellulose. The instant application is particularly directed to the products resulting from the use of oxidized parafiin wax.

What I claim is 1. Paper carrying oxidized wax.

2. Paper carrying a blown mixture of wax and petroleum oil.

3. Paper containing blown wax in a state of incipient oxidation.

4. Paper containing blown wax free from objectionable resinous substances capable of contaminating foodstufis.

5. Oxy-parafiined paper.

6. Paper waterproofed with a wax dispersion, a portion at least of the wax content bein oxidized parafiin.

7. aper waterproofed with air blown parafiin wax.

8. Paper carrying oxidized hydrocarbons of substantially non-pigmenting power.

9. Paper carrying blown wax in an amount sufiicient to produce a waxed eifect in the paper.

10. Paper carrying blown wax softened with an, oil.

11. A paper product carrying paraffin wax blown to a state of incipient oxidation.

12. A paper product carrying oxidized paraflinwax and another wax.

13. A paper product carrying a blown mixture of waxes.

14. Paper carrying an oxidized mixture of waxes one of which is paraflin wax, and petroleum oil.

15. A paper product carrying a blown wax and a aper size.

16. aper carrying oxidized parafiin and a rosin size.

41 meaeee 17. A calenfiered paper product carrying blown Wax.

' 18. A. hot calendered paper profluct carrying oxidized parafin wax.

19. Paper containing hydrocellulose and carrying Oxidized wax.

20. A paper product made from paper containing hydrocellulose and carrying blown parafin wax.

21. A calendered paper product made from paper containing hydrocellulose and. carrying oxidized parafin and a rosin size.

' CARLETQN ELLIS. 

